driver.java

Java程序设计(美) David D. Riley著 机械工业出版社 书籍配套 代码

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/** Traversal of Oval List Program  (Figure 11.11)
 *  Author: David D. Riley
 *  Date: JANUARY, 2005
 */
public class Driver implements ActionListener {
	private JFrame window;
	private JButton greenBtn, blueBtn, coordinateBtn;
	private	SimpleList<Oval> ovalList;
	
	/** post:	window is created 
	 *			and  a row of black ovals spans window horizontally
	 *			and  the row of ovals is stored in ovalList 
	 */
	public Driver()  {   
		Oval tempOval;
		int horizontalPos;	
		window = new JFrame("Manipulate the Ovals");
		window.setBounds(10, 10, 600, 500);
		window.setVisible(true);
		window.setLayout(null);
		greenBtn = newButton(20, 430, "Color Green");
		blueBtn = newButton(210, 430, "Color Blue");
		coordinateBtn = newButton(400, 430, "Print Coordinates");
		ovalList = new SimpleList<Oval>();
		
		horizontalPos = 5;
		ovalList.reset();
		while  ( horizontalPos < window.getWidth() )   {
			tempOval = new Oval(horizontalPos, 100, 10, 10);
			window.add(tempOval, 0);
			ovalList.add( tempOval );
			horizontalPos = horizontalPos + 15;
		}	
		window.repaint();
	}

	/**	pre:	window != null  <br>
	 *	post:	result is a newly created button
	 *			and  result.getX()==x  and  result.getY()==y
	 *			and  result.getWidth()==180  and  result.getHeight()==30
	 *			and  result.getParent() == window's pane
	 *			and  this is the action listener for result 
	 */
	public JButton newButton(int x, int y, String s)   {
		JButton button;
		button = new JButton(s);
		button.setBounds(x, y, 180, 30);
		button.addActionListener(this);
		window.add(button, 0);
		return button;
	}

	/**	post:	greenBtn was clicked
	 *				implies all ovals are recolored green
	 *			and  blueBtn was clicked
	 *				implies  all ovals are recolored blue
	 *			and  coordinateBtn was clicked
	 *				implies the X coordinate of all ovals are output 
	 */
	public void actionPerformed(ActionEvent e)   {
		if (e.getSource() == coordinateBtn) {
            for (Oval tempOval : ovalList)  {
				System.out.println( "X coordinate of oval: " + tempOval.getX() );
            }
		} else {  // either greenBtn or blueBtn was clicked
            for (Oval tempOval : ovalList)  {
				if (e.getSource()==greenBtn)
					tempOval.setBackground( Color.green );
				else
					tempOval.setBackground( Color.blue );
                tempOval.repaint();
            }
		}
	}
}